As technological development and a need for mobile instruments have increased, a demand for secondary batteries as energy sources has increased rapidly. Among such secondary batteries, lithium secondary batteries having high energy density and voltage, long cycle life and a low discharging rate have been commercialized and used widely. A lithium secondary battery includes a positive electrode, a negative electrode and a separator interposed between the positive electrode and the negative electrode, and the electrode, such as a positive electrode or negative electrode, is obtained by applying electrode slurry containing an electrode active material, binder and a solvent to an electrode current collector, and carrying out drying and rolling.
Such a method for manufacturing an electrode is problematic in that the solvent evaporates upwardly from the electrode while the electrode is dried and the polymer binder moves along the direction of solvent evaporation, and thus the distribution of the polymer binder in the electrode active material layer becomes non-uniform. In addition, since the polymer binder is distributed non-uniformly, the adhesion between an electrode collector and an electrode active material layer is decreased, resulting in degradation of the output of a battery.